There is created a body politic and corporate, a unit of local government, named the Southwest Suburban Railroad Redevelopment Authority, embracing the townships of Bloom, Thornton, Calumet, Bremen, Orland, Worth, Rich, and Palos. The Authority shall continue in existence until the accomplishment of its objective, the relocation of railroad tracks and roadways and the grade separation of railroads from the right-of-way and at-grade crossing closures within the Southwest Suburban area, or until the Authority officially resolves that it is impossible or economically unfeasible to fulfill that objective.